Absorbent article and method for manufacturing an absorbent article

ABSTRACT

An absorbent article having a main body having a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core sandwiched between the topsheet and the backsheet is disclosed. The main body has longitudinal and transversal axes. The article has two wings extending asymmetrically outwardly from a crotch portion of the main body in opposite directions with respect to the longitudinal axis. The wings are provided with means for fastening them to a garment when folded over the main body and towards the longitudinal axis. Each wing has an outer edge which defines at least one arc of a circle having a radius coinciding with a section of the outer edge. The section extends between a first point and a second point along the outer edge where the arc no longer coincides with the outer edge. The radius is between 40-500 mm. Also disclosed is a method for manufacturing the absorbent article.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a U.S. National Phase application of PCT/EP2018/068232, filed Jul. 5, 2018, which claims priority to PCT/EP2017/067068, filed Jul. 7, 2017 and PCT/EP2017/067071, filed Jul. 7, 2017, the disclosures of all which are incorporated herein by reference in their entireties for all purposes.

TECHNICAL FIELD

The present disclosure concerns an absorbent article comprising a main body having a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core sandwiched between said topsheet and said backsheet, said main body being arranged along a longitudinal axis and a transversal axis extending in a perpendicular direction in relation to the longitudinal axis, said main body defining a front portion, a back portion and a crotch portion; wherein said article comprises a first wing and a second wing extending outwardly from said crotch portion of the main body in opposite directions in an asymmetric manner with reference to the longitudinal axis, and generally along said transversal axis, said wings being provided with fastening means configured for fastening said wings to a garment when being folded over said main body and towards said longitudinal axis.

The present disclosure also relates to a method for manufacturing an absorbent article having a longitudinal extension along a longitudinal axis and a transverse extension along a transverse axis, said article defining a front portion, a back portion and a crotch region. Furthermore, the method comprises the steps of: forming a main body by providing a liquid-permeable topsheet, providing a liquid-impermeable backsheet and sandwiching an absorbent body between said topsheet and said backsheet; forming a first wing and a second wing configured so as to extend outwardly from said main body in opposite directions and generally along said transversal axis; and providing said wings with fastening means for fastening said wings to a garment when being folded over said main body and towards said longitudinal axis.

BACKGROUND

Absorbent articles, for example in the form of sanitary napkins and panty liners, are well known. The general purpose of such absorbent articles is to absorb, distribute and store various types of body exudates while providing a high level of comfort and sense of dryness to the wearer during use of the absorbent article. Also, such absorbent articles are arranged to prevent the wearer from getting the clothes soiled by body exudates.

A conventional sanitary napkin is normally designed with a main body which comprises a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core which is sandwiched between the topsheet and the backsheet. The main body is arranged along a longitudinal axis and a transversal axis which extends in a perpendicular direction in relation to the longitudinal axis.

Furthermore, absorbent articles in the form of sanitary napkins are often provided with two wings, i.e. two wing-shaped fastening elements, extending outwardly from the main body in opposite directions and generally along the transversal axis. The purpose of the wings is to allow fastening of the sanitary napkin to an undergarment of a user. To this end, the wings are arranged to be folded over the main body and towards said longitudinal axis. In order to allow fastening of the sanitary napkin to the undergarment, each wing is provided with fastening means such as an adhesive material. In this manner, the sanitary napkin can be attached and held in place in the undergarment during use.

According to prior art, the wings of a sanitary napkin can be formed in a symmetrical manner, i.e. so that the entire sanitary napkin can be said to define a contour which is symmetrical with reference to its longitudinal axis. Alternatively, it is also known that the wings can be formed in an asymmetrical manner with reference to the longitudinal axis.

A previously known absorbent article having asymmetrical wings of the above-mentioned type is known from the patent document U.S. Pat. No. 5,401,268. This document shows a sanitary napkin having two wings which are arranged asymmetrically along opposite sides of a longitudinal edge of the napkin.

The wings disclosed in U.S. Pat. No. 5,401,268 are formed of two triangular pieces which comprise semi-circular indentations on the base of said pieces, and also a rounded cutout at the top of each triangular piece. The purpose of the wings shown in U.S. Pat. No. 5,401,268 is to provide a relatively large surface for fixing the sanitary napkin to an undergarment.

Even though the article disclosed in U.S. Pat. No. 5,401,268 fulfills the basic requirements regarding absorbent articles provided with wing-shaped fastening elements, there is a need for further improvements within this field of technology. Firstly, there is a requirement that the wings must be configured to attach the napkin to an undergarment in a secure manner, in particular so as to improve the comfort for the wearer. This means that the attachment of the wing-shaped elements must not cause any unwanted shearing forces in the undergarment, or any other causes of instability of the fastening of the article to an undergarment.

Also, there are continuing efforts made in order to provide more cost-effective manufacturing methods for the products of this type, including methods for forming the wings.

In particular, there is an increasing requirement to provide a more optimized use of a fastening means, comprising an adhesive, on each wing. In this regard, manufacturers of absorbent articles are often limited to using strips of adhesive material applied on each wing. In such a process, there is a need to use a sufficient amount of adhesive, while at the same time minimizing the use of release paper, which is regarded as causing a relatively high cost.

Furthermore, in an embodiment, the adhesive material must be used on the wings in a manner so that it does not give rise to any unwanted forces in the garment of the user, which otherwise may cause discomfort.

Furthermore, the traditional manner of manufacturing absorbent articles of the above-mentioned type has a drawback in that it relies to a great extent to cutting operations involving straight edges. Such straight edges may not always be optimal for the comfort of the user.

Furthermore, the traditional way of designing absorbent articles with asymmetrically arranged wings leads to a risk that a user folds a wing over the other wing when the article is to be used, i.e. so that the adhesive on the first wing is positioned on the backside of the second wing (instead of being placed on the user's undergarment), which is a disadvantage.

Consequently, there is a need for further improvements within the relevant field of technology.

SUMMARY

In accordance with the present disclosure, there is provided an absorbent article with the purpose of solving the above-mentioned problems related to prior art within this field. In particular, the article is configured so as to provide a secure and stable attachment of a sanitary napkin to an undergarment, in order to provide a high level of comfort for the wearer while also providing the required absorbent properties. Also, the present disclosure aims at contributing to a cost-effective manufacturing process for sanitary napkins and also reducing a risk that a user folds a wing over the other wing during use, i.e. so that the adhesive on the first wing is positioned on backside of the second wing instead of on the user's undergarment.

In accordance with the present disclosure, this object is obtained by means of an absorbent article comprising a main body having a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core sandwiched between said topsheet and said backsheet, said main body being arranged along a longitudinal axis and a transversal axis extending in a perpendicular direction in relation to the longitudinal axis, said main body defining a front portion, a back portion and a crotch portion; wherein said article comprises a first wing and a second wing extending outwardly from said crotch portion of the main body in opposite directions in an asymmetric manner with reference to the longitudinal axis, and generally along said transversal axis, said wings being provided with fastening means configured for fastening said wings to a garment when being folded over said main body and towards said longitudinal axis. Furthermore, each wing is formed with an outer edge which defines at least one arc of a circle coinciding with a section of the outer edge and having a defined radius, said section extending between a first point on the outer edge and a second point along said outer edge where said arc no longer coincides with said outer edge, and wherein said radius is within the interval of 40-500 mm.

The disclosure provides certain advantages. Firstly, it fulfills the requirements on sanitary napkins to be securely fitted and held in place in an undergarment of a wearer. In particular, it is provided due to the fact that a relatively large part of the available adhesive provided on the wings will be positioned close to the longitudinal axis of symmetry of the sanitary napkin during use of the sanitary napkin.

Furthermore, the configuration of the wings according to the disclosure, involving an outer edge with the above-mentioned arc of a circle, leads to a further advantage of the invention in that the risk that a user folds a wing over the other wing during use so that the adhesive on the first wing is positioned on the second wing will be reduced. The fact that the wings are formed with an arc-shaped outer edge as defined above will minimize this risk.

The absorbent article may be configured so that said outer edge includes a first point in the form of a transversally outermost point, said section extending from said outermost point and to said second point along said outer edge where said arc no longer coincides with said outer edge.

The outer edge may define two or more arcs of a circle, each of said arcs defining a curve-shaped section and having a defined radius, said first radius and said second radius both being within the interval of 40-500 mm. According to another embodiment, the absorbent article may be configured so that the radius is within the interval of 50-400 mm. Furthermore, the radius may be within the interval of 50-300 mm.

Furthermore, said outer edge may include at least one straight section. According to the present disclosure a straight section is defined as a section which defines a curve-shaped section having a radius being above 600 mm.

Each wing may be configured to define a first straight line between the first point and the second point, and a second straight line along an upper edge section, wherein the first line defines a second angle (α2) with respect to the longitudinal axis and wherein the second line defines a third angle (α3) with respect to the longitudinal axis, the magnitude of each angle (α2, α3) being chosen so that α2<α3, or α2>α3, or α2=α3.

The absorbent article may be configured so that the magnitude of said second angle (α2) is chosen so that: 10°<α2<65°.

The absorbent article may be configured so that the magnitude of said third angle (α3) is chosen so that: 60°<α3<120°.

Furthermore, each wing may be formed with an area between said fastening means and a further edge which constitutes a grip tab.

The wings may extend generally along a common straight line which defines a first angle (α1) with respect to said transversal axis which exceeds 0° but which is less than 45°. The straight line may extend between said first point on the outer edge of the first wing and a corresponding point on the outer edge on the second wing. The first point and said corresponding point may be constituted by transversally outermost points along the corresponding outer edges. The first angle (α1) may be within the interval 10°-35°.

Furthermore, absorbent article may be configured so that the first wing comprises a first fastening means and the second wing comprises a second fastening means, said first and second fastening means may be off-set from each other in the longitudinal direction of the article.

The fastening means may be covered, during manufacturing, by a release layer.

Also, a first distance, as defined between the outer edge of each wing and the longitudinal axis, may be in the range of 40-100 mm.

Also, a second distance, as defined between the first wing folding edge and the corresponding outer edge may be in the range of 20-60 mm.

Furthermore, a second wing folding edge may be defined where each wing can be folded during use of the article and may have a length which is within the interval 10-80% of the full length of the main body, and preferably 25-65% of the full length of the main body.

Also, the absorbent article may be configured so that each longitudinal side of the absorbent core at least partly defines a core edge which is generally parallel to the longitudinal axis.

The absorbent core may generally follow the outer edge of the main body and define an edge region of the main body which is generally equally wide along the entire periphery of the absorbent core.

The fastening means may be in the form of one or more fastening areas. The fastening means may be in form of one or more areas which comprises an adhesive material on each of said wing.

The areas may be generally rectangular and positioned on each wing so that they are displaced in relation to each other in the longitudinal direction of the article.

Also, the areas may extend along generally the entire transversal length of each corresponding wing or only along a part of the entire transversal length of each corresponding wing.

Furthermore, said wings may be formed with an area between said fastening means and a further edge which constitutes a grip tab.

Also, the absorbent article may comprise a further fastening means positioned along the main body on a garment-facing side of said backsheet.

Furthermore, there is provided a method for manufacturing an absorbent article having a longitudinal extension along a longitudinal axis and a transverse extension along a transverse axis, said article defining a front portion, a back portion and a crotch region, said method comprising: forming a main body by providing a liquid-permeable topsheet, providing a liquid-impermeable backsheet and sandwiching an absorbent body between said topsheet and said backsheet; forming a first wing and a second wing configured so as to extend outwardly from said main body in opposite directions in an asymmetric manner with reference to the longitudinal axis and generally along said transversal axis; and providing said wings with fastening means for fastening said wings to a garment when being folded over said main body and towards said longitudinal axis. Furthermore, the method comprises the following steps: forming each wing with an outer edge which defines at least one arc of a circle coinciding with a section of the outer edge and having a defined radius; forming said section so as to extend between a first point on the outer edge and a second point along said outer edge where said arc no longer coincides with said outer edge; and forming each wing so that said radius is within the interval of 40-500 mm.

Further advantages and advantageous features of the present disclosure are disclosed in the following description and in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail below with reference to the figures shown in the appended drawings.

FIG. 1 shows a view from above of an absorbent article in the form of a sanitary napkin according to an embodiment of the invention;

FIG. 1A shows an enlarged portion of the article according to FIG. 1;

FIG. 2 shows a cross-sectional view of the sanitary napkin;

FIG. 3 shows a view from above of the sanitary napkin shown in FIGS. 1 and 2 but in a condition as manufactured;

FIG. 4 shows a further embodiment of the invention;

FIG. 5 shows a further embodiment of the invention;

FIG. 5A shows an enlarged portion of the article according to FIG. 5; and

FIG. 6 shows a further embodiment of the invention.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

Different aspects of the present disclosure will be described more fully hereinafter with reference to the enclosed drawings. The embodiments disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein.

With initial reference to FIG. 1, there is shown a view from above of an absorbent article in the form of a sanitary napkin 1 manufactured in accordance with an embodiment of the present disclosure. The sanitary napkin 1 is based on an absorbent structure for absorbing body exudates from a wearer.

From FIG. 1 it can be understood that the sanitary napkin 1 comprises a main body 2 with a liquid-permeable topsheet 3 and a liquid-impermeable backsheet 4. The sanitary napkin 1 also comprises an absorbent core 5 which is sandwiched between the topsheet 3 and the backsheet 4. The topsheet 3 is arranged at the surface of the sanitary napkin 1, i.e. the side facing the wearer. The backsheet 4 is arranged at the underside of the sanitary napkin 1, i.e. the side facing an undergarment (not shown) of the wearer. Furthermore, both the topsheet 3 and the backsheet 4 extend laterally outside of the absorbent core 5 along the whole perimeter of the main body 2.

The absorbent core shown in FIG. 1 has a substantially rectangular design. However, the absorbent core is not limited to this particular design but can be formed in generally any geometric form within the scope of the present disclosure.

According to further embodiments, one or more additional layers may be provided in the absorbent article 1. For example, an acquisition layer may be arranged between the absorbent core 4 and the topsheet 3. Such an additional layer can for example be in the form of an airlaid layer, a spunlace layer, a high-loft, foam or any other type of material layer which may be used in an absorbent article in order to act as a liquid acquisition and absorption layer. The acquisition layer is adapted to quickly receive and temporarily store discharged liquid before it is absorbed by the absorbent core. Such acquisition layer may be composed of for example airlaid nonwoven, spunlace nonwoven, high loft nonwoven or foam materials. An airlaid nonwoven can be produced with fluff, wood pulp, and here the fluff fibres are dispersed into a fast moving air stream and condensed onto a moving screen by means of pressure and vacuum. The web can be bonded with resin and/or thermal plastic resin dispersed with the pulp. The web can be thermobonded (by heat), latex bonded (by adhesive) or multibonded (a combination of thermo and latex bonding) or mechanically bonded (high compression and temperature, bonding by hydrogen). The grammage of the airlaid nonwoven may be for example from 50 to 100 gsm.

The topsheet 3, backsheet 4 and the absorbent core 5 may consist of or comprise any materials suitable for their particular purposes, as will be discussed in further detail below. Also, the above-mentioned layers 3, 4, 5 may be connected to each other by any conventional means such as by means of an adhesive, heat bonding or ultrasonic bonding.

Furthermore, and although not shown in the drawings, the sanitary napkin 1 can be configured in a manner having different material layers, densities or material components as seen along a horizontal plane of the sanitary napkin 1, i.e. in addition to being configured with different layers in the vertical direction.

As shown in FIG. 1, the sanitary napkin 1 has a longitudinal extension along a longitudinal axis Y1 and a transverse extension along a transverse axis X1. Furthermore, the sanitary napkin 1 can be said to be divided into a front portion 6, a back portion 7 and a crotch portion 8. The front portion 6 is intended to be oriented in a direction towards the wearer's belly during use of the sanitary napkin 1.

Furthermore, according to the embodiment, the sanitary napkin 1 is formed with two fastening wings 9, 10, or fastening tabs, which are configured for fastening the napkin 1 to an undergarment of the wearer. More precisely, the sanitary napkin 1 comprises a first wing 9 and a second wing 10, each of which extends outwardly from the main body 2 and in opposite directions. The wings 9, 10 extend generally along the direction of the transversal axis X1. Also, the wings 9, 10 are provided with fastening means 11, 12, which according to the embodiment are in the form of one or more adhesive areas which are configured for fastening the wings 9, 10 to the undergarment when the wings 9, 10 are folded under the main body 2 in a direction towards the longitudinal axis Y1.

Furthermore, each adhesive area of the fastening means 11, 12 can be said to define a centre point 34, 35, corresponding to a centre of mass for said adhesive area. According to known technology, such a centre point can be defined for any area, irrespective of its shape.

Each wing 9, 10 has an outer edge 14, 15 which according to an embodiment shown in FIG. 1 is curve-shaped, i.e. it defines an outwardly extending curve along the longitudinal direction of the absorbent article 1. In particular, the outer edge 14 of the first wing 9 defines a first point 29 which is an outermost point in the sense that it defines a point along the outer edge 14 which has the greatest distance to the longitudinal axis Y1 of all the points along the outer edge 14. The curve-shaped outer edge 14 is formed in a manner so as to provide certain advantages, as mentioned above.

In order to obtain these advantages, the outer edge 14 defines in particular at least one arc 30 of a circle which coincides with a section 31 of the outer edge 14 and has a defined radius r. The section 31 extends between the first point 29 and a second point 32 along the outer edge 14 where the arc 30 no longer coincides with said outer edge 14.

In the embodiment shown in FIG. 1, the first point 29 is constituted by the transversally outermost point 29 of the outer edge 14. The invention is however not limited to this embodiment only, as will be described in greater detail below. With reference to FIG. 1, the section 31 of the outer edge 14 extends from the outermost point 29 and to the second point 32 where the arc 30 does not coincide with the outer edge 14.

In a corresponding manner, the second wing 10 is shaped in the same manner as the first wing 9 and has a second outer edge 15 with a second point 33 which is an outermost point in the same sense as the first point 29, i.e. it defines a point which has the greatest distance to the longitudinal axis Y1 of all the points along the second outer edge 15.

An advantage with the above described curve-shaped outer edges 14,15 is that the risk that a user folds a wing 9 over the other wing 10 during use so that the adhesive on the first wing 9 is positioned on the backside of the second wing 10 will be reduced. The purpose of the adhesive on the wings 9, 10 is to fasten the wings 9, 10 on the user's undergarment, and if instead the wings 9, 10 are attached to each other, the user may have difficulty in removing the article 1 after use, which is a disadvantage.

FIG. 1A is an enlarged view showing a portion of the article 1 involving the arc 30 of a circle and the section 31. As shown in the embodiment of FIG. 1A, the outer edge 14 is formed in a manner so that it defines an arc 30 of a circle which extends along the outer edge 14 and coincides with a section 31 of said outer edge 14. The arc 30 of a circle has a defined radius r, which according to the embodiment may be within the interval 40-500 mm. Furthermore, the section 31 extends between the first point 29 and the second point 32, wherein said second point 32 is a point along the outer edge 14 where the arc 30 no longer coincides with the outer edge 14. The fact that the wing 9 comprises said curve-shaped section 31 leads to certain advantages, as mentioned above.

As indicated in FIG. 1, the two wings 9, 10 are arranged in an asymmetrical manner so that they extend generally along a common straight line 13 which defines an angle α1 with respect to the transversal axis X1. According to an embodiment, the magnitude of said angle α1 exceeds 0° but is less than 45°. According to a particular embodiment, said angle α1 may be within the interval 10-35°. It should be noted that the wings 9, 10 can be arranged so that they are displaced in relation to each other in the longitudinal direction of the sanitary napkin 1.

In order to clearly define the extension of the above-mentioned straight line 13 shown in FIG. 1, it can be noted that said straight line 13 extends through the above-mentioned first point 29 and second point 33. In the embodiment according to FIG. 1, these points 29, 33 correspond to the transversally outermost points along the outer edges 14, 15.

FIG. 2 is a cross-sectional view as seen along the straight line 13 shown in FIG. 1. The absorbent core 5 is sandwiched between the topsheet 3 and the backsheet 4. As mentioned above, an acquisition layer 5 a, suitably of airlaid material, can be arranged between the absorbent core 5 and the topsheet 3. Also, the two wings 9, 10 are formed so as to extend in opposite directions from the main body 2. According to the embodiment, each of the wings 9, 10 is provided with fastening means in the form of at least one adhesive area 11, 12, which is applied on the underside of each wing 9, 10, i.e. on the side which does not face the wearer. Furthermore, the main body 2 is also provided with further fastening means 18 for the purpose of fastening the sanitary napkin 1 onto an inner surface of an undergarment. Such further fastening means 18 may be in the form of one or several adhesive sections 18 which are arranged on the rear side of the backsheet 4 and which are arranged to extend along the longitudinal direction of the sanitary napkin 1.

As shown in FIG. 2, the adhesive sections 18 are covered with a release paper layer 19 when the sanitary napkin 1 is in its non-used condition. When the sanitary napkin 1 is to be used, the release paper layer 19 is removed by the user so that the sanitary napkin 1 can be fastened to the undergarment.

According to alternative embodiments, the sanitary napkin 1 can be provided with various types of fastening means in the form of frictional fasteners, mechanical fasteners such as a hook-and-loop fastener, or combinations of different types of fasteners, as previously known.

The properties and design of the various layers 3, 4, 5 which form part of the sanitary napkin 1 will now be described more in detail, with reference primarily to FIGS. 1 and 2.

According to an embodiment, the topsheet 3 is formed by a fluid permeable nonwoven fabric or film which is made of thermoplastic synthetic fibers. The topsheet 3 is sufficiently liquid-permeable to allow discharged body fluids to penetrate through the thickness of the topsheet 3. Also, the topsheet 3 is suitably manufactured from a material which is compliant and soft-feeling to the skin of the wearer.

According to different embodiments, the topsheet 3 may be manufactured from various web materials such as for example nonwoven films, foams, or combinations of the above-mentioned materials. The topsheet 3 may also be perforated.

Furthermore, the backsheet 4 is constituted by a liquid-impermeable and breathable layer such as a polymeric film, for example a film of polyethylene or polypropylene. According to different embodiments, the materials which can be used for the backsheet 4 include thin and flexible fluid impermeable plastic films, or fluid impermeable nonwoven materials, fluid impermeable foams and fluid impermeable laminates.

According to the embodiment shown in the drawings, the backsheet 4 is formed by a single layer, but can alternatively be formed by a multi-layered structure, i.e. a laminate, wherein at least one layer is fluid impermeable. Furthermore, the backsheet 4 can optionally be elastic in any direction. Also, backsheet materials which are not fully liquid impermeable but only resistant to fluid penetration may be used, particularly in cases where relatively small amounts of body exudates are expected to be absorbed by the sanitary napkin 1.

According to further embodiments, the backsheet 4 may be breathable, implying that air and vapor may pass through the backsheet 4. Furthermore, the backsheet 4 may optionally have an outer, garment-facing surface of a textile material such as nonwoven.

Furthermore, the wings 9, 10 are formed in a manner in which the topsheet 3 and the backsheet 4 are laminated and formed with the wings 9, 10 being integrated as shown in the drawings. This means that the outer edges 14, 15 are cut in the desired form during a manufacturing process for the sanitary napkin 1. According to an alternative embodiment, which is not shown in the drawings, the wings can be manufactured separately and then supplied and finally attached to the main body during a final manufacturing process.

Furthermore, according to the embodiment shown in FIGS. 1 and 2, the sanitary napkin 1 comprises an absorbent core 5 which is formed by one or more layers comprising fibres of cellulosic fluff pulp. According to alternative embodiments, the absorbent core 5 can be made up of any suitable absorbent or fluid-absorbing material as known in the art, for example foam, fiber waddings and similar materials. As mentioned above, different types of material layers can be used, alone or in combination, for example airlaid, spunlace and highloft material, depending on the required properties and the field of use of the sanitary napkin 1 in question.

According to one embodiment, the absorbent article is a liner, in which case the absorbent core may only be made of one thin material, for example a nonwoven layer.

According to a further embodiment, the absorbent core 5 comprises a suitable amount of superabsorbent particles. Such superabsorbent material is well known in the field of absorbent articles, and is constituted by a water-swellable and water-insoluble material which is capable of absorbing large quantities of fluid upon formation of a hydrogel. Normal superabsorbent materials are capable of absorbing fluids of at least 10 times its own weight. According to an embodiment, the amount of said superabsorbent particles is at least 10% by weight, i.e. in relation to the total weight of the absorbent core 5.

The superabsorbents are mixed into the material of the absorbent core 5. The absorbent core 5 may further incorporate components for improving the properties of the absorbent core 5. Some examples of such components are binder fibers, fluid-dispersing materials, fluid acquisition materials, etc. as known in the art. According to an embodiment, a mixture of cellulose fluff pulp and superabsorbent articles is mixed in a generally homogeneous manner throughout the entire absorbent core 5.

According to further embodiments, the absorbent core 5 may be a homogeneous structure or may be a layered structure with laminates of the same or different materials. The absorbent layers may have uniform thickness or may vary in thickness in different parts of the layers. Also, the basis weight and composition of the absorbent core 1 may vary within such absorbent layers.

Furthermore, as known by the skilled person, the various layers of the sanitary napkin 1 can suitably be attached by means of layers of adhesive material. Such adhesive layers are not shown in the drawings.

With reference to FIG. 1, the wing 9 is formed so that a further straight line 20 is defined as extending through the first point 29 and the second point 32. Also, a further straight line 21 a is formed along an upper edge section 21 of the wing 9. More precisely, the first-mentioned line 20 defines a further angle α2 with respect to the longitudinal axis Y1 and the second line 21 a defines a yet further angle α3 with respect to the longitudinal axis Y1. In the embodiment shown in FIG. 1, the magnitude of each angle α2, α3 is chosen so that α2<α3. However, the invention is not limited to such an embodiment only, but can alternatively be arranged in a manner in which α2>α3, or even α2=α3.

The second wing 10 is arranged in a similar manner as the first wing 9 but is reversed (i.e. “upside-down”) as compared with the first wing 9, i.e. with lines corresponding to the above-mentioned lines 20, 21 a.

According to the shown embodiment, the wings 9, 10 are arranged in a generally parallel manner, while being connected to the main body 2 in a slightly displaced manner as regarded in the view according to FIG. 1.

Consequently, the wings 9, 10 form an asymmetric design due to the design of the wings 9, 10 and also due to the fact that they extend generally along the above-mentioned common straight line 13 which defines an angle α1 with respect to the transversal axis X1.

According to the embodiment shown in FIG. 1, the angle α3 between the line 21 a and the longitudinal axis Y1 is greater than 90°, which means that a relatively small area 24 is formed between the adhesive area 11 and the upper edge section 21, which area 24 is not covered with any adhesive. This area 24 forms a grip tab which simplifies gripping and handling of the wings 9, 10 during fastening of the sanitary napkin 1 in an undergarment, and also during removal of the sanitary napkin 1 from the undergarment. It should be noted that a grip tab can be provided even in the case in which the angle α3 between the line 21 a and the longitudinal axis Y1 is less than 90°.

In the following, certain dimensions and measurements relating to an embodiment of the invention will now be described with reference to FIG. 1. As indicated, a first distance d1, as defined between the outermost point 29, 33 of each wing (here shown only with reference to the second wing 10) and the longitudinal axis Y1 is in the range of 40-100 mm, preferably 50-90 mm, most preferably 60-90 mm. According to a particular embodiment, the first distance d1 is approximately 77 mm. This corresponds to the distance from the centre of the absorption body 4 to the outermost points 29, 33 of each wing 9, 10.

Furthermore, a first wing folding edge 26 is defined as a part of the longitudinal side of the main body 2 where each wing 9, 10 meets the main body 2 and along which each wing 9, 10 can be folded when the sanitary napkin 1 has been manufactured. The first wing folding edge 26 as shown in FIG. 1 is defined as a line which is parallel to the longitudinal axis Y1.

Consequently, the first wing folding edge 26 is defined as part of the longitudinal side of the main body 2 where each wing 9, 10 meets the main body 2 and along which each wing 9, 10 is folded when the absorbent article 1 is manufactured.

As mentioned, the first wing folding edge 26 defines a line along which the corresponding wing 10 can be folded during manufacturing of the sanitary napkin 1. During use of the sanitary napkin 1, however, the wings 9, 10 are normally folded along a line which is adapted to the size of the undergarment. Consequently, as also shown in FIG. 1, a second wing folding edge 26 a is defined as a line along which each wing 9, 10 can be expected to be folded during use of the sanitary napkin 1. According to embodiments, the second wing folding edge 26 a is configured so that the length along which it is folded is within the interval 10-80% of the full length of the main body, and preferably 25-65% of the full length of the main body, depending on the size and the desired properties of the sanitary napkin 1.

A second distance d2 can be defined between the first wing folding edge 26 and the corresponding outermost point 30 of the corresponding wing 10, said second distance d2 being in the range of 20-60 mm, preferably 25-50 mm, most preferably 24-45 mm. According to a particular embodiment, the second distance d2 is approximately 39 mm. A further way of defining the magnitude of the second distance d2 is by defining it in relation to the full width of the sanitary napkin 1. According to embodiments, the ratio between the second distance d2 and the full width is in the range of 12-39%, preferably 16-32%, most preferably 16-29%.

Furthermore, a core edge 27 can be defined along at least a part of each longitudinal side of the absorbent core 5. As shown in FIG. 1, the core edge 27 is generally parallel to the longitudinal axis Y1. Also, a third distance d3, as defined between the core edge 27 and the outermost point 33 of the corresponding wing 10, is in the range of 29-69 mm, preferably 34-65 mm, most preferably 34-61 mm. According to a particular embodiment, the third distance d3 is approximately 49 mm. A further way of defining the magnitude of the third distance d3 is by defining it in relation to the full width of the sanitary napkin 1. According to embodiments, the ratio between the third distance d3 and the full width is in the range of 18-45%, preferably 21-42%, most preferably 21-40%.

Also, a fourth distance d4 is defined between the core edge 27 and the longitudinal axis Y1, said fourth distance d4 being in the range of 10-50 mm, preferably 15-45 mm, most preferably 20-40 mm. According to a particular embodiment, the fourth distance d4 is approximately 29 mm. A further way of defining the magnitude of the fourth distance d4 is by defining it in relation to the full width of the sanitary napkin 1. According to embodiments, the ratio between the fourth distance d4 and the full width is in the range of 6-33%, preferably 9-29%, most preferably 12-25%.

Also, the core edge 27 is according to the embodiment shown in the drawings generally parallel with the longitudinal axis Y1. In other embodiments, however, the core edge can be non-parallel in relation to the longitudinal axis Y1. In such cases, the above-mentioned distances d3 and d4 will be dependent on the position along the longitudinal axis Y1.

Furthermore, the absorbent core 5 is formed with a periphery which generally follows the outer edge of the main body 2 and defines an edge region 28 along the entire periphery of the main body 2.

Also, the fastening means 11, 12 which is arranged on each one of the wings 9, 10 is according to an embodiment in the form of an area which supports an adhesive material. These adhesive areas 11, 12 are generally rectangular and positioned on each wing 9, 10 in a manner so that they are displaced in relation to each other in the longitudinal direction of the article 1, and also so that they extend along generally the entire transversal length of each corresponding wing 9, 10.

The arrangement of the fastening means 11, 12 according to the invention provides an advantage in that it increases the stability of each wing 9, 10. Also, the sanitary napkin 1 can be positioned and attached to an undergarment in a secure and comfortable manner, without any shearing forces acting on the undergarment, which otherwise could be detrimental to the comfort of the wearer.

FIG. 3 shows the sanitary napkin according to FIGS. 1 and 2 but in a condition as manufactured, i.e. with the wings 9, 10 being folded. Not all components and features of the sanitary napkin 1 which are shown in FIGS. 1 and 2 are indicated with reference numerals in FIG. 3.

As indicated in FIG. 3, the main parts of the adhesive areas 11, 12 are located close to the longitudinal axis Y1. Also, the adhesive areas 11, 12 are displaced in relation to each other along the longitudinal direction of the sanitary napkin 1. This contributes, during use of the sanitary napkin 1, to a secure and comfortable fit for the user, while maintaining adequate absorption properties.

Also, the adhesive area 11 on the first wing 9 defines a first centre point 34 whereas the adhesive area 12 on the second wing 10 defines a second centre point 35. According to the embodiment, the fastening means 11, 12 are positioned on each wing 9, 10 in a manner so that the fastening means 11, 12 are not positioned along a common longitudinal direction of the article 1 as produced, and also when the wings 9, 10 are positioned as intended during use when the wings 9, 10 are fastened to the user's undergarment. This means that the position of the first wing 9 does not coincide with the position of the second wing 10 as mirrored along the machine direction 26 a of the article 1, i.e. along the second wing folding edge 26 a shown in FIG. 1.

FIG. 3 shows an embodiment in which the outer edges 14, 15 of the wings 9, 10 are folded towards the longitudinal axis Y1. It should be noted that the outer edges can extend a further distance over the main body 2, i.e. so that they extend over the longitudinal axis Y1. It should be noted that, irrespective of the actual positions of the outer edges 14, 15, it is advantageous if the adhesive areas 11, 12 are positioned—when the wings 9, 10 are folded—in a manner so that they overlap and cooperate with the adhesive sections 18 on the rear side of the main body 2 during use.

Although not shown in FIG. 3, the fastening means 11 of the first wing 9 and the fastening means 12 of the second wing 10 may be covered, during manufacturing of the article 1, by means of a release layer, which may be in the form of a rectangular release paper.

According to a further embodiment which is shown in FIG. 4, the fastening means 12 can be formed by a number of relatively small areas 12 a, 12 b, 12 c which together cover an area of the corresponding wing 10. These small areas 12 a, 12 b, 12 c can be rectangular, as shown in FIG. 4, or can be of any other, suitable form in order to cover a suitable area of the corresponding wing 10. As an alternative to the embodiment in FIG. 4, the small areas can be arranged so that the extend for example in a direction which is transverse to the longitudinal axis Y1. Also, in a manner which is similar to FIG. 1, the small areas 12 a, 12 b, 12 c shown in FIG. 4 are placed so that a grip tab 25 is formed.

FIG. 5 shows an embodiment of the invention in which the outer edge 14 of the wing 9 defines a first arc 30 a of a circle coinciding with a first section 31 a of said outer edge 14, and a second arc 30 b of a circle coinciding with a second section 31 b of said outer edge 14. The first arc 30 a has a first radius ra, whereas the second arc 30 b has a second radius rb. Consequently, this embodiment shows that the invention can be formed so that the outer edge 14 comprises two or more sections with mutually different curvature. The first section 31 a may or may not be arranged in a manner so that the first arc 30 a includes the transversally outermost point 29 of the outer edge 14 (see also FIG. 1). The embodiment shown in FIG. 5 shows a first section 31 a which does not extend from the outermost point 29 of the outer edge 14 but, as mentioned, the invention is not limited to such an arrangement only.

FIG. 5A is an enlarged view showing a portion of the first wing 9 and in particular showing the first arc 30 a of a circle and the second arc 30 b of a circle and the corresponding sections 31 a and 31 b, respectively.

According to a further embodiment, the outer edge can be shaped in a manner so that a generally straight section extends between the first arc 30 a and the second arc 30 b. Such an embodiment is shown in FIG. 6. Accordingly, FIG. 6 shows an embodiment in which the outer edge 14 defines a first arc 30 a of a circle coinciding with a first section 31 a of the outer edge, and a second arc 30 b of a circle coinciding with a second section 31 b of said outer edge 14, and also a straight section 36 of the outer edge 14 which is positioned between the first section 31 a and the second section 31 b. The first arc 30 a has a first radius ra, whereas the second arc 30 b has a second radius rb. Consequently, this embodiment shows that the invention can be formed so that the outer edge 14 comprises two or more sections with mutually different curvature and a further straight section 36 positioned between the first and section sections 31 a, 31 b.

A process for manufacturing the sanitary napkin 1 described above comprises a number of steps which will now be described. Initially, a material which constitutes the absorbent core 4 is sandwiched between the backsheet 2 and the topsheet 3 in a manner which is known as such. In this manner, the main body 2 is formed. Subsequently, the first wing 9 and the second wing 10 are formed in a manner so that they extend outwardly from the main body 2, in opposite directions and generally along said transversal axis X1, as described above. Furthermore, the wings 9, 10 are provided with fastening means 11, 12 for fastening the wings 9, 10 to a garment when they are folded over the main body 2. Furthermore, the manufacturing method comprises the step of forming each wing 9, 10 with an outer edge 14 which defines at least one arc 30 of a circle coinciding with a section 31 of the outer edge 14 and having a defined radius r, said section 31 extending between a first point 29 and a second point 32 along said outer edge 14 where said arc 30 no longer coincides with said outer edge 14.

After manufacturing of the sanitary napkin 1, it is packaged by first folding the back portion 7 and the front portion 6 over the crotch portion 8, after which the folded napkin 1 is wrapped in an individual wrapping and stored in a box. Alternatively, the front portion 6 can be folded first over the crotch portion 8, after which the back portion 7 is folded over the crotch portion 8 and the folded napkin 1 is then wrapped.

As mentioned above with reference to FIG. 3, the wings 9, 10 are folded along the first folding edge 26 during the manufacturing step. During manufacturing, however, the sanitary napkin 1 can alternatively be folded in a manner in which the wings 9, 10 and parts of the edge region 28 are folded along the core edge 27. This means that the width of the folded product can be made less than according to prior art, which is an advantage since the quantity of some of the material needed, in particular the release paper 19 and the wrapping material, can be reduced.

The invention is not limited to the embodiment but can be varied within the scope of the appended claims. For example, the particular shape of the wings 9, 10 may vary within the scope of the claims. Also, the materials and dimensions used for the different layers forming the absorbent article 1 can be varied, as indicated above. Also, all embodiments of wings and other geometries can be reversed as compared with the shown embodiments. 

The invention claimed is:
 1. An absorbent article comprising a main body having a liquid-permeable topsheet, a liquid-impermeable backsheet and an absorbent core sandwiched between said topsheet and said backsheet, said main body being arranged along a longitudinal axis (Y1) and a transversal axis (X1) extending in a perpendicular direction in relation to the longitudinal axis (Y1), said main body defining a front portion, a back portion and a crotch portion; wherein said article comprises a first wing and a second wing extending outwardly from said crotch portion of the main body in opposite directions in an asymmetric manner with reference to the longitudinal axis (Y1), and generally along said transversal axis (X1), said wings being provided with first and second fastening means configured for fastening said wings to a garment when being folded over said main body and towards said longitudinal axis (Y1), wherein each wing includes a periphery defined by an outer edge that faces away from the longitudinal axis (Y1) in an unfolded state of the article and at least one side edge that faces inwardly towards the longitudinal axis (Y1) in the unfolded state of the article and connects the outer edge to the main body, with the outer edge of each wing defining at least one arc of a circle coinciding with a section of the outer edge and having a defined radius (r), said section extending between a first point on the outer edge and a second point along said outer edge where said arc no longer coincides with said outer edge, wherein said radius (r) is within an interval of 50-300 mm, and wherein said outer edge includes said first point in the form of a transversally outermost point of the wing, said section extending from said outermost point and to said second point, and wherein the outer edge of each wing is formed with no straight edge sections.
 2. The absorbent article according to claim 1, wherein said outer edge defines two or more arcs of a circle, each of said arcs defining a curve-shaped section and having a defined first radius (ra) and second radius (rb), said first radius (ra) and said second radius (rb) both being within the interval of 40-500 mm.
 3. The absorbent article according to claim 1, wherein each wing defines a first straight line between the first point and the second point, and a second straight line along an upper edge section at the at least one side edge, wherein the first line defines a second angle (a2) with respect to the longitudinal axis (Y1) and wherein the second line defines a third angle (a3) with respect to the longitudinal axis (Y1), a magnitude of each angle (a2, a3) being chosen so that a2<a3, or a2>a3, or a2=a3.
 4. The absorbent article according to claim 3, wherein the magnitude of said second angle (a2) is chosen so that: 10°<a2 <65°.
 5. The absorbent article according to claim 3, wherein the magnitude of said third angle (a3) is chosen so that: 60°<a3 <120°.
 6. The absorbent article according to claim 3, wherein each wing is formed with an area between said fastening means and a further edge which constitutes a grip tab.
 7. The absorbent article according to claim 1, wherein said wings extend generally along a common straight line which defines a first angle (al) with respect to said transversal axis (X1) which exceeds 0° but which is less than 45°.
 8. The absorbent article according to claim 7, wherein the first angle (a1) is within an interval of 10°-35°.
 9. The absorbent article according to claim 7, wherein said straight line extends between said first point on the outer edge of the first wing and a corresponding point on the outer edge on the second wing.
 10. The absorbent article according to claim 9, wherein said first point and said corresponding point are constituted by transversally outermost points along the corresponding outer edges.
 11. The absorbent article according to claim 1, wherein said first and second fastening means are covered, during manufacturing, by a release layer.
 12. The absorbent article according to claim 1, wherein a first distance (d1), as defined between the outer edge of each wing and the longitudinal axis (Y1), is in a range of 40-100 mm.
 13. The absorbent article according to claim 12, wherein a second distance (d2), as defined between a first wing folding edge and the corresponding outer edge is in a range of 20-60 mm.
 14. The absorbent article according to claim 13, wherein a second wing folding edge is defined where each wing can be folded during use of the article, said second wing folding edge having a length which is within an interval of 10-80% of a full length of the main body.
 15. The absorbent article according to claim 1, wherein each longitudinal side of the absorbent core at least partly defines a core edge which is generally parallel to the longitudinal axis (Y1).
 16. The absorbent article according to claim 1, wherein the absorbent core generally follows the outer edge of the main body and defines an edge region of the main body which is generally equally wide along an entire periphery of the absorbent core.
 17. The absorbent article according to claim 1, wherein said fastening means is the form of one or more areas which supports an adhesive material on each of said wing.
 18. The absorbent article according to claim 17, wherein the areas are generally rectangular and positioned on each wing so that they are displaced in relation to each other in a longitudinal direction of the article defined along the longitudinal axis (Y1).
 19. The absorbent article according to claim 17, wherein the areas are arranged extend along generally an entire transversal length of each corresponding wing.
 20. The absorbent article according to claim 17, wherein said wings are formed with an area between said fastening means and a further edge which constitutes a grip tab.
 21. The absorbent article according to claim 1, wherein it comprises a further fastening means positioned along the main body on a garment-facing side of said backsheet.
 22. A method for manufacturing an absorbent article having a longitudinal extension along a longitudinal axis (Y1) and a transverse extension along a transverse axis (X1), said article defining a front portion, a back portion and a crotch region, said method comprising: forming a main body by providing a liquid-permeable topsheet, providing a liquid-impermeable backsheet and sandwiching an absorbent body between said topsheet and said backsheet; forming a first wing and a second wing configured so as to extend outwardly from said main body in opposite directions in an asymmetric manner with reference to the longitudinal axis (Y1) and generally along said transversal axis (X1); and providing said wings with fastening means for fastening said wings to a garment when being folded over said main body and towards said longitudinal axis (Y1); forming each wing with a periphery defined by an outer edge that faces away from the longitudinal axis (Y1) in an unfolded state of the article and at least one side edge that faces inwardly towards the longitudinal axis (Y1) in the unfolded state of the article and connects the outer edge to the main body, with the outer edge of each wing defining at least one arc of a circle coinciding with a section of the outer edge and having a defined radius (r); forming said section so as to extend between a first point on the outer edge and a second point along said outer edge where said arc no longer coincides with said outer edge; and forming each wing so that said radius (r) is within an interval of 50-300 mm; and forming each wing so that said outer edge includes said first point in the form of a transversally outermost point, said section extending from said outermost point and to said second point, wherein the outer edge of each wing is formed with no straight edge sections. 